Manifold Absolute Pressure Sensor
2018 Ford F-150 · 5.0L V8 Coyote
Sensor Type
piezoresistive
Waveform Type
dc-variable
Location
Mounted on driver side of intake manifold near throttle body, or integrated into throttle body assembly depending on production year
Pins
3-pin connector
Timebase
500ms/div
Voltage Scale
1V/div
Trigger
N/A - DC signal
Wiring
Light Green/White (MAP signal to PCM), Gray/Red or Red/White (5V reference), Black/White (sensor ground)
Expected Voltage Range
At Idle
0.8V to 1.5V
At Higher RPM
4.2V to 4.8V
Expected Pattern
Smooth DC voltage reflecting manifold vacuum, low at idle (high vacuum), high at WOT (atmospheric pressure)
Known-Good Waveform
At idle (warm engine, closed throttle), voltage should read 0.8-1.5V corresponding to 16-20 inHg vacuum. At key-on engine-off, should read 4.5-4.8V (atmospheric pressure). Signal should transition smoothly during throttle changes without steps, dropouts, or electrical noise.
Common Failure Patterns
Signal stuck at 4.5V or no change with throttle input
Cause: Failed MAP sensor diaphragm, clogged vacuum port, or disconnected vacuum hose
Erratic signal or rapid fluctuations during idle
Cause: Intermittent electrical connection, damaged sensor, or severe engine vacuum leak causing unstable manifold pressure
Related DTCs: P0106
Diagnostic Tips
Coyote engines may use MAP sensor for backup fuel control or EVAP system monitoring rather than primary fuel metering (MAF-based). Verify 5V reference voltage is stable; Ford systems are sensitive to voltage reference issues affecting multiple sensors simultaneously.
Related Diagnostic Trouble Codes
P0105P0106P0107P0108P0109
Always confirm waveform data with your vehicle's OEM service manual before diagnosing.
Free, no signup. View all waveforms for this vehicle